Plasmonic nanosensors: Review and prospect

Recent progress in plasmon-based sensors has greatly overcome the limitations of conventional optical sensors, in terms of sensitivity, tunability, photostability, and in vivo applicability, by employing nanostructured materials. In this review, we summarize three types of plasmon-based nanosensors categorized by the geometries of sensing platforms as plasmonic transducers, which are planar nanofilm, periodic nanoarrays, and individual nanoparticles, respectively. We then introduce the notable accomplishments to enhance the sensing performances for each sensing platform. Additionally, we present recent works for signal enhancement strategy based on the targeted nanoassemblies of particles, which can be applied to all plasmon-based sensing platforms. The focus of this review will be on how plasmonic nanostructures can be applied to detect biological and chemical analytes, and notable approaches to improve the sensitivity.